Listen for dripping sounds. As simple as this step may seem, it may be overlooked in a busy, noisy home. Even though a dripping faucet may not seem to waste significant amounts of water, over the course of day, each individual drop adds up to thousands and thousands of drops, or gallons and gallons of water. Choose a time when there is little or no activity, such as early in the morning, or late at night, when the house is very quiet.
Look for evidence of a leak along the base board of walls near the location of your plumbing fixtures. Pipes that contain water under pressure can become corroded, develop loose fittings, or crack because of freezing, allowing a continuous loss of water until repaired. Mildew or mold, darkened surfaces, or even puddles of water may occur below leaks. If the problem is inside the wall cavity, it may be necessary to remove the paneling, plaster, or wallboard to correct it.
- Pipes also may sweat when cold water passes through them in warmer interior air-spaces in the home, and this water condensing on the surface of pipes may drip, causing moisture problems to appear where no leak exists.
Listen for noises from your commodes/bathrooms, to determine if they are running at unusual intervals, when no one has recently flushed them. When there is a seal leak in the water closet (toilet), the tank will drain slowly over a period of time, until the water level drops sufficiently for the float valve to open and replenish it. Sticking flush valves and leaking seals in toilets can waste a lot of water, since, like dripping faucets, the flow, although perhaps very small, is continuous.
- Check the supply valves on lavatories and commodes if they are leaking. The packing, which seals the valve stem of a typical stop (water valve) seals when compressed just enough to "pack off" leak paths, but not so tightly that turning the handle is difficult. Turn the packing nut (top nut surrounding the stem) slightly clockwise (shouldn't require more than 1/8 turn or so) and see if this stops the leak around the stem. #*Supply valves are meant to be fully opened or completely closed. Turn the valve off by turning the handle clockwise until it stops; Open the valve by turning the handle counter-clockwise (anti-clockwise) until it stops. Occasionally, a very slight leak of a stem will stop if the valve was partly opened and is either fully closed or opened fully.
- See also How to Fix a Running Toilet and How to Fix a Slow Toilet.